Play with the points
Juegue con los puntos
Punto D = intersección de las líneas Ab y aB
Punto E = intersección de las líneas Ac y aC
Punto F = intersección de las líneas Bc y bC
Pappus' Theorem (part 1/4)
Let three points A, B, C be incident to a single straight line and another three points a,b,c incident to (generally speaking) another straight line. Then three pairwise intersections D = Bc∩bC, E = Ac∩aC, and F = Ab∩aB are incident to a (third) straight line.
Pascal's theorem (parts 2/4, 3,4 y 4/4) is a generalization of Pappus's (hexagon) theorem
Reference: http://en.wikipedia.org/wiki/Pascal's_theorem and http://www.cut-the-knot.org/pythagoras/Pappus.shtml
http://www.geogebratube.org/material/show/id/78735 (1/4)
http://www.geogebratube.org/student/m78735
http://www.geogebratube.org/material/show/id/78737 (2/4)
http://www.geogebratube.org/student/m78737
http://www.geogebratube.org/material/show/id/78738 (3/4)
http://www.geogebratube.org/student/m78738
